RS66542B1 - Method for the disassembly of a textile article - Google Patents

Description

Description

TECHNICAL FIELD

[0001] The invention relates to a procedure for disassembling textile products, in which textile products can be disassembled automatically or semi-automatically.

STATE OF THE ART

[0002] The textile industry is the second most polluting industry in the world (after the petrochemical industry). Today, one truck full of textiles is thrown away every second. Only 1% of the materials used in the textile industry are recycled. Every year, $50 billion worth of material is not reused (source: Mac Arthur Foundation). These facts, although to a lesser extent, also apply to the furniture industry and other textile-based industries. Examples of these are clothing, footwear, furniture, floor coverings, mattresses, bedding and automotive parts such as airbags, seat covers and seat belts.

[0003] The vast majority of textile-based products consisting of several components cannot be reused at the end of their useful and expected lifetime or are very difficult to recycle into usable products.

[0004] Discarded textile products generally end up in incinerators or landfills. If they are still recycled, they are cut into small pieces using a shredder. In the best case, the different materials that made up the product are then separated: the shredded pieces are sorted according to their material type under the influence of air pressure and centrifugal forces. It is an energy-intensive and complex process that leads to a lower quality and economic value of the recycled material.

[0005] Because the recycled material has a lower quality than the original material, it cannot be reused in the same industry or for the same original application. Recycled textiles and leather, for example, are mainly used in insulation mats, textiles and canvas for moving, and as a filler for the production of concrete and polymers. This type of recycling is also known as "down-cycling".

[0006] The decline in the quality of recycled material is mainly due to two factors. First, as a result of chopping, the size of the material is quite limited, which leads to a decrease in the mechanical characteristics of the material and a corresponding decrease in value. Secondly, the lower purity of recycled materials also plays a role. Most textile products are actually made from different materials, each of which requires a different recycling procedure. Contamination of one material with another material is the main reason for the lower quality of recycled textile materials.

[0007] Both chemical and mechanical recycling processes also have difficulties with hard points, such as zippers and buttons. During mechanical recycling (i.e. fiberizing) and chemical recycling (i.e. de- and repolymerization processes, such as processes for econyl (econyle) on the one hand and viscose (visocosis) such as SaXcell (saxell), Refibra and Renewcell, on the other hand), hard points cause jams and damage to machines. Hard spots must therefore be removed before starting the recycling process. This act is called extraction of hard points (délissage) and today it is carried out in two ways: on the one hand manually, and on the other hand with stronger and rougher fiber-dissolving devices, such as the Exel cutter by Laroche. Unfortunately, manual removal of hard spots is economically inefficient, and research has shown that coarser fiberizers produce fibers that are too short (poor quality).

[0008] Consequently, there is a need for a process to efficiently separate or disassemble individual parts of textile products during the recycling process, which prevents material contamination, easily removes hard spots, and increases the efficiency and quality of existing recycling processes.

[0009] Such a procedure is known from EP2861793. EP2861793 describes a sewing process with a built-in disassembly function. The procedure from EP2861793 is based on the chemical change of used yarns based on electromagnetic radiation. That procedure is time-consuming and difficult to apply on a large scale. Disassembly according to the procedure of EP2861793, for example, takes place in a Faraday cage, as a result of which it is not possible to carry out the disassembly as a continuous process. Moreover, this procedure does not allow specific disassembly and only allows disassembly of entire products.

[0010] WO2013/189956 describes a system for assembling and disassembling textile products. WO2013/189956 is based on electromagnetic radiation, which is time-consuming and difficult to implement on a large scale.

[0011] EP0967314 and EP0800808 describe the use of fusible yarns in knitted products and absorbent products, respectively. The procedures described in EP0967314 and EP0800808 do not apply to garments that are sewn, nor do they facilitate their assembly or disassembly.

[0012] JP2001254331 describes the use of low and high melting point yarns in the production of continuous corrugated sheets for erosion control, however, it does not relate to the assembly or disassembly of garments.

[0013] The present invention aims at finding at least one solution for some of the above-mentioned problems or shortcomings.

THE ESSENCE OF THE INVENTION

[0014] For the foregoing, the invention provides a process according to patent claim 1. In the first aspect, the invention relates to a process for disassembling textile products, in which textile products can be disassembled automatically or semi-automatically because yarn from a polymer melt is used and in which disassembly of the manufactured product takes place by heating the product or yarn to a temperature equal to or higher than the melting temperature, as a result of which the points loosen.

[0015] The impact of the textile industry on the environment should not be underestimated. The textile industry is the second most polluting industry in the world. The subject invention provides a method for solving that problem. Thanks to the invention, the amount of textile products that are discarded without being recycled or reused can be drastically reduced.

[0016] The built-in disassembly function makes délissage (removal of hard points such as buttons and zippers) easy and convenient, due to which, during mechanical and chemical recycling, the mechanical characteristics of the recycled material can subsequently be maintained even better. In addition, the method according to the present invention enables easy disassembly of textile products consisting of several components at the end of their useful or expected life. This avoids possible contamination of recycled materials caused by non-disassembly or poor disassembly of different parts. Since the decline in the quality of recycled materials coming from the textile industry is mainly caused by the decline in the mechanical characteristics of the material as well as the lower degree of its purity, the subject invention enables the skilled worker to obtain high-quality recycled products coming from the textile industry.

[0017] Dismantling and reuse of high-quality materials leads, on the one hand, to great financial savings in the processing of textile waste and, on the other hand, raw materials for the production of new textile products are also obtained in this way, so that the financial savings continue in the production of new textile products. Thanks to the possibility of carrying out the disassembly process semi-automatically or fully automatically, it is - in contrast to existing processes for recycling textile products - a time-saving process and therefore also a relatively inexpensive process. Calculations have shown that the price compared to current known manual procedures can be reduced by at least 20% and more.

[0018] The built-in disassembly function according to the present invention is based on the use of polymer melt yarns for quilting or sewing textile products during the manufacturing process of these textile products. Separation of different parts and materials of textile products can be easily done by heating the yarn. More specifically, said melt yarn may comprise one or more longitudinally parallel filaments, wherein the melting temperature of the filaments is set between 80°C and 200°C.

[0019] The invention can be introduced into the textile industry without the need for significant changes to production facilities. Melt yarn is actually suitable for use in existing sewing machines and provides strong points.

[0020] Although not part of the claimed invention, for purposes of illustration, the present disclosure also relates to textile products that can be disassembled automatically or semi-automatically. The materials obtained thanks to the invention after disassembling textile products can be used as raw materials for the production of new textile products thanks to the preservation of their mechanical characteristics and their high degree of purity. In this way, the subject invention helps not only in reducing the huge amount of waste caused by the textile industry and the accompanying pressure on our ecological system, but also in reducing the consumption of energy and water, which is associated with the production of new, unused textile materials.

DESCRIPTION OF IMAGES

[0021]

Figure 1 shows a schematic illustration of the production of textile products according to the subject representation.

Figure 2 shows a possible design of a heating unit for disassembling textile products.

DETAILED DESCRIPTION

[0022] The invention relates to end-of-life processes of textile products and provides a method for disassembling textile products, in which textile products can be disassembled automatically or semi-automatically. Contrary to the state of the art, the procedure is based on a change of physical phase, which is also known as a change of aggregate state, which is obtained by a change in the temperature of the environment, in this case by raising the temperature. It is a different process from the one that exists in the prior art, as described in EP2861793, where radiation is used to adjust the mechanical characteristics of the material. Such radiation induces depolymerization and subsequent reduction in mechanical properties. In the process as described here, no chemical reaction and therefore no depolymerization takes place. The process is based only on the physical change of phase in which the yarn goes from a solid state to a "liquid" state. Thanks to the complex range of yarns with a specific melting temperature, only the used yarn will melt at a higher temperature, and the textile product and its components will remain unchanged. It is important here that these yarns have a high thermal conductivity, while the yarns used in radiation separation will mainly have an insulating function.

[0023] The subject methodology, yarns and devices contribute to a simple and ecological way of disassembling textile products and therefore contribute to the improvement of the circular economy, which can be applied on a large scale.

[0024] Unless otherwise stated, all terms used in the description of the invention, including technical and scientific terms, shall have the meaning as generally understood by one skilled in the art of the invention. For a better understanding of the description of the invention, the following terms are explained more precisely.

[0025] Singular forms in the document refer to both the singular form and the plural form unless the context clearly indicates otherwise. "Segment", for example, means one or more than one segment.

[0026] When "approximately" or "about" is used in the document together with a measurable quantity, parameter, period or moment, etc., variations of /- 20% or less, preferably /- 10% or less, more preferably /- 5% or less, even more preferably /- 1% or less, and even more preferably /- 0.1% or less from the stated value are meant, as long as such variations apply to the invention which is described. It will be clearly understood, however, that the very value of the quantity with which the term "approximately" or "about" is used is specified.

[0027] The terms "include", "which includes", "consist of", "consisting of", "provide", "contain", "containing", "comprising", "comprising" are synonymous and include open terms that indicate the presence of what follows, and do not exclude or prevent the presence of other components, features, elements, members, steps that are known or described in the prior art.

[0028] Specifying numerical intervals using endpoints includes all integers, fractions, and/or real numbers between the endpoints, including those endpoints.

[0029] "Textile" is a material that can be transformed, consisting of filaments (endless threads) or fibers (short pieces of thread). Textiles can be one-, two- or three-dimensional.

[0030] The term "textile product" or "textile-based product" is used herein to denote items that are at least partially composed of textiles and/or leather (animal skin or synthetic leather). Non-limiting examples of textile products are clothing and footwear, protective clothing such as cut gloves, protective clothing and ballistic jackets, household textile products such as cleaning cloths, floor cloths, sheets, blankets, dish cloths, towels, tablecloths and handkerchiefs, home furnishing textiles such as net curtains, curtains, carpets, floor coverings, furniture covers and sunshades; technical textile products such as canvas, tents, parachutes, screens, ropes; geotextiles such as shore protection, erosion protection, reinforcement for road foundations, reinforcement for rubber, as in bicycle and car tires, conveyor belts, pipes, rubber boats, and textile products for vehicles, such as cars, trains and aircraft, such as airbags, seat covers and seat belts.

[0031] The terms "automatic" and "semi-automatic" refer, within the context of the present invention, to a process in which the disassembly of textile products does not take place manually, but, on the contrary, is done completely (automatically) or to a large extent (semi-automatically) by means of a machine or device.

[0032] "Yarn" or thread is used to refer to thread made by spinning fibers or to refer to filament yarns, which are essentially endless and therefore already form a yarn. In the context of the present invention, a distinction is made between "standard yarn" and "melt yarn".

[0033] The term "standard yarn" includes both sewing thread and embroidery thread. The term "standard thread" refers to, among other things, quilting threads that are mainly intended for sewing two pieces together, decorative threads (such as metallic threads or thicker threads) and closed stitch threads that are optimal for use in closed stitch machines. The term "standard yarn" further refers to threads that are generally known and used in the textile industry for the production of textile products. In particular, a standard yarn will be a yarn made from a material selected from the group consisting of cotton, linen, polyester, rayon, wool, nylon, silk, or combinations thereof. These yarns will furthermore not melt in the melting temperature range of melt yarns and therefore will not undergo physical change at temperatures set within the melting temperature range of melt yarns.

[0034] The term "melt yarn" refers to a yarn with a known melting point or melting temperature, at which the yarn melts when heated to a temperature within the yarn's melting temperature range.

[0035] The term "sewing" refers to the processing and production of something using a needle and thread, such as, for example, attaching parts to each other using a needle and thread. Sewing can be done manually or by machine. When a sewing machine is used for sewing, the term "quilting" is used. The term "sewing" therefore also includes mechanical quilting with needle and thread.

[0036] The term "thermoplastic polymer" refers to a polymeric material that undergoes a change in physical state under the influence of temperature. Therefore, a thermoplastic polymer will become soft or (semi)liquid under the influence of heat and will become solid again when cooled. In particular, a thermoplastic polymer will change from a solid state to a liquid state when heated to a temperature greater than or equal to the melting point of the polymer. The term "polymer" is used to denote an organic compound whose molecules consist of a series of identical or similar parts, monomers, which are chemically linked to each other. The term "melting point" or "melting temperature" therefore refers to the temperature at which the transition from a solid or soft state to a liquid state takes place by breaking down mainly secondary compounds, such as van der Waals bonds (van der Waals) and hydrogen compounds.

[0037] The term "monofilament" refers to threads consisting of only one filament, as opposed to the term "multifilament" which refers to threads consisting of more than one filament.

[0038] "Twinned" yarn is obtained by "twisting" several yarns. Here, "twisting" refers to the twisting together of at least two yarns into a single yarn, in which the characteristics of the resulting composite yarn are different from those of the individual yarns.

[0039] The "Thickness" of the yarn is described in the present invention by means of mass number and/or length number. The "mass number" of the yarn corresponds to the mass in grams of 1000 m of yarn in which 1 g / 1000 m is designated in the technical field as "1 tex". The "length number" of the yarn corresponds to the number of times a length of 1.6934 m of yarn fits into 1 gram.

[0040] "Tensile strength" is a measure of the maximum tensile force exerted on the yarn ends just before the yarn breaks under the increasing tensile force.

[0041] Yarn "elasticity" describes the maximum increase in length when the maximum pulling force is exerted on the ends of the yarn without breaking the yarn.

[0042] In a first aspect, the invention relates to a method for disassembling textile products, in which textile products can be disassembled, and therefore recycled or reused, automatically or semi-automatically. In particular, the textile product includes melt yarn, where the melt yarn has a melting temperature and where the transition of the melt yarn from a solid phase to a liquid or semi-liquid phase is at a temperature equal to or higher than the melting temperature of the yarn and where disassembly is performed by subjecting the product to a temperature equal to or higher than the melting temperature of the melt yarn. According to the invention, the melt yarn will be used with a melting temperature set between 80° C and 200° C and where the disassembly will be performed by subjecting the product to a temperature equal to or higher than the melting temperature of the melt yarn. Although not part of the claimed invention, for purposes of illustration, the present disclosure also relates to filaments that are partially or completely made of molten polymer with a melting temperature within the range of 60° C. to 200° C. When exposed to temperatures within that temperature range, the filaments will disintegrate. The subject invention therefore relates to a process for disassembling filaments from products, where the filaments can be disassembled, and therefore recycled or reused, automatically or semi-automatically, and where the filaments are at least partially made of molten polymer and where the molten polymer will transition from a solid phase to a liquid phase at a temperature equal to or higher than the melting temperature of the polymer and where the disassembly is performed by heating the filament and/or the product to a temperature equal to or higher than melting of molten polymer. Preferably, the melting temperature of the molten polymer will be set between 60°C and 200°C, preferably between 80°C and 200°C.

[0043] Although not part of the invention for which protection is sought, for purposes of illustration, the subject representation relates to a melt yarn comprising one or more longitudinal parallel filaments, as well as a thread, where the melting temperature of the filaments is set between 60° C and 200° C, preferably between 80° C and 200° C, preferably between 110° C and 190° C, between 160 and 190° C, preferably between 130° C and 180° C, most preferably between 150° C and 190° C.

[0044] Most textile products are made of different materials, each of which requires a different procedure for recycling. Contamination of one material with another leads to a reduced quality of recycled textile materials. The various materials present in the textile products made according to the present invention can, thanks to the use of polymer melt yarns, be disassembled in a non-destructive manner into units consisting of only one material. Thus, the purity of the obtained recycled material is maintained. As a result, these textile products, after use, can be easily recycled, efficiently and qualitatively, and the mechanical characteristics of the recycled material can be better maintained.

[0045] Since the decline in the quality of recycled materials coming from the textile industry is mainly caused by the decline in the mechanical characteristics of the material, as well as the reduced degree of its purity, the present invention enables the skilled worker to obtain high-quality recycled products coming from the textile industry.

[0046] It is important to note that only 1% of materials in the textile industry are recycled. Each year, the single use of textile materials leads to the waste of materials worth approximately 40 billion dollars. Therefore, it is clear that there is a huge financial potential in the recycling of textile products. It is possible to answer this by reusing or recycling materials in the textile industry using the subject invention. On the one hand, the disassembly and reuse of high-quality materials leads to enormous financial savings in the processing of textile waste. On the other hand, in this way, raw materials can be obtained for the production of new textile products, so that financial savings increase in the production of new textile products. Thanks to the possibility to carry out the disassembly process semi-automatically or fully automatically, it is - in contrast to the existing processes for recycling textile products - a time-saving process and therefore also a relatively inexpensive process.

[0047] The display can be introduced into the textile industry without the need for significant changes in production facilities. Melt yarn is actually suitable for use in existing sewing machines and provides strong points.

[0048] The textile industry is the second most polluting in the world. Today, one truck full of textiles is thrown away every second. Discarded textile products generally end up in incinerators or landfills. The impact of the textile industry on the environment is enormous. The subject invention provides a method for solving that problem. Thanks to this invention, the amount of textile products that are discarded, not recycled or reused can be drastically reduced. In addition, the materials that, thanks to the invention, are obtained after disassembling textile products can be used as raw materials for the production of new textile products. In this way, the subject invention helps not only in reducing the huge amount of waste caused by the textile industry and the accompanying pressure on the ecological system, but also in reducing the consumption of energy and water, which is associated with the production of new, unused textile materials.

[0049] The built-in disassembly function according to the present invention is based on the use of polymer melt yarns for quilting or sewing textile products during the production process of those textile products. Separation of different parts and materials of textile products can be performed by heating the yarn to a temperature equal to or higher than the melting temperature of the yarn from the melt. The melting temperature of polymer melt yarn is higher than 80° C. At a lower melting temperature, the integrity of the assembled textile products could be compromised in everyday situations where the products are exposed to higher temperatures, such as in washing machines or dryers. In addition, the temperature of the melt yarn can be raised, by friction, when the yarn is used for sewing with industrial sewing machines. Also, the melting temperature of at least 80°C guarantees that the yarn from the melt will not melt during the production of textile products. On the other hand, the melting temperature of polymer melt yarn is lower than 200° C, since it is possible that synthetic textile materials also melt at temperatures higher than 200° C, so that they are lost or may cause unwanted contamination with other materials. Preferably, the melt temperature of the polymer melt yarn is set between 110° C and 180° C, most preferably between 150° C and 190° C. The inventors have determined that when using a melt yarn with a melt temperature set between 150° C and 180° C, the likelihood of the product accidentally coming apart is the lowest since there is little chance of the product being accidentally exposed to that temperature. On the other hand, most of the synthetic materials that make up textile products will not be affected at that temperature.

[0050] Sewing or processing or production of textile products using needle and thread is possible with different types of points. In addition, the advantage of the process according to the present invention is that it can be carried out using sewing machines as they are currently used in the textile industry, without the need to first adjust or replace them for the aforementioned. This means that the implementation of these procedures does not require large investments by companies.

[0051] In the textile industry, for sewing different types of points, different sewing machines are used that make points that generally fall into one of the following four categories. The first type of stitch is chain stitch. This stitch is usually obtained from a single thread that forms a loop by itself. In this case, it is enough to replace the thread with the melt yarn. Preferably, for the production of textile products according to the further development of the subject invention, during sewing, at least one melt yarn is used in combination with at least one standard yarn. This is the case when the remaining three types of points are formed.

[0052] Another type of stitch and the corresponding machine is a closed stitch (eng. lock stitch), which is also used in home sewing machines and in which two yarns are used: "upper yarn" and "lower yarn". They are crossed over each other and thus a stitch is made. With this type of stitch, it is sufficient to replace at least one of the two yarns with a melt yarn in order to subsequently obtain a built-in disassembly function according to the method of the invention. In addition, it is common for only the top yarn to be visible in the finished textile product. Preferably, the lower yarn is made up of melt spun yarn and the upper yarn is made up of standard yarn. In this way, the built-in disassembly function is combined with the aesthetic aspects of the standard yarn, where no special adjustments have to be made with respect to the aesthetic aspects of the textile product or production facilities (namely, the sewing machine).

[0053] The third type of stitch, the "overlock stitch" and the corresponding "overlock" or "serger" machine, is obtained by making a series of loops of yarn that are sewn over the edge of the fabric of the fabric parts of the textile product. The "edge" stitch can also be used to sew edges and seams. Generally, when sewing with an edge stitch, at least three threads are used. Here too, it is possible to replace at least one yarn with a melt yarn in order to incorporate a disassembly function during the manufacturing process of the textile product. Depending on the type of edge stitch and the total number of yarns used to make the stitch, it may be necessary to replace more than one yarn with melt yarn, which will be apparent to the skilled worker after he or she has studied the stitch.

[0054] A fourth type of stitch, the "cover stitch" or flat stitch looks like two parallel closed stitches when viewed from above and a border stitch when viewed from below. Just like the edge stitch, this stitch is also made up of several upper yarns and lower yarns.

[0055] During sewing or quilting, as suitable for the formation of different points, which are used for quilting between two lower parts of textile products, according to a further development of the invention, at least one melt yarn is used, whether it is combined or not with a standard yarn. When heated, the melt yarn will melt causing the stitch to lose its stitching capacity and the textile product to break into different parts.

[0056] In one embodiment of the present invention, at least one of the (bottom) yarns is replaced by a melt yarn in order to incorporate a disassembly function during the production process of the textile product. By using a standard yarn for the upper yarn, the aesthetic aspect of the points remains unchanged. In another embodiment, a melt yarn is used for both the bottom yarn and the top yarn, wherein the melt yarn selected may be the same yarn for the bottom and top yarns or a melt yarn having different characteristics (such as, for example, tensile strength, dtex, polymer nature, etc.)

[0057] Despite the fact that there are countless types of stitches, they can generally be considered a variation of one of these four types of stitches, and it will be clear to the skilled worker which yarn is preferable to replace with melt yarn when performing the process according to the present invention.

[0058] As previously stated, the subject embodiment is compatible with existing industrial sewing machines. Moreover, as a result of the choice of the yarn to be replaced by the melt yarn, the invention can be carried out without disturbing the aesthetic aspect of the textile product since the visible yarn is still a standard yarn. Consequently, the introduction of the invention into the current textile industry requires almost no financial investment in the form of adapted equipment or replacement of all yarns.

[0059] According to the invention, the polymer is a thermoplastic polymer with a melting temperature set between 80° C and 200° C, whereby the thermoplastic polymer is selected from the group of polyolefins, polyesters, polypropylene, polyurethane, polyoxymethylene (POM), polyamides such as polyamide 11 (PA11), polylactic acid (PLA) and their copolymers.

[0060] Polyolefins are polymers exclusively based on carbon and hydrogen, whereby the most famous polyolefins are polyethylene or polyethylene (PE), polypropylene or polypropylene (PP), polybutylene or poly(1-butene) and (PB) polyisobutylene or polyisobutene (PIB). Of course, melt yarns can also be composed of lesser-known polyolefins with desired characteristics. Polyolefins also include copolymers, for example, but are not limited to ethylene vinyl acetate (EVA) or copolymers of ethene with acrylate esters.

[0061] In one embodiment, the yarn is made from bio-sourced plastic. Bio-based plastics are polymers that are made from plant-based materials, preferably from renewable sources. These polymers have a much smaller impact on the environment than conventional polymers. An example of such bio-sourced plastic yarn is based on PA11 or polyamide 11. PA11 is a high-quality, lightweight polymer that is made from castor oil, extracted from the seeds of Ricinus communis.

[0062] Thermoplastic polymers are particularly suitable for use in the melt yarns of the present invention. First, the melting point of these polymers can be selected depending on the application, and these polymers can easily be processed into filaments by extrusion, making them suitable as raw materials for melt yarns. Second, these thermoplastic polymers are characterized by their soft or pliable state at normal ambient temperatures, which is necessary for use as yarn in the textile industry since most textile products do not have a rigid structure. Finally, when heated, these polymers will become liquid above their melting point, rather than degrading or burning. Thanks to these characteristics, textile products made with the melt yarn can be disassembled by heating the melt yarn to a temperature set within the range of the polymer's melting point. In this case, the polymer will melt without damaging the textile product, which is the result of, for example, degradation or burning of the yarn. Examples of melt yarns suitable for use in the present invention are shown in Table 1 and the examples.

[0063] According to a further embodiment of the invention, the thermoplastic polymer consists of one polymer or several polymers. Preferably, the melt yarn is composed of one type of thermoplastic polymer, more preferably, if possible, the thermoplastic polymer of which the melt yarn is composed is the same polymer as the type of textile to which it is sewn. The advantage of this is that, when disassembling the textile product, the yarn residue from the polymer melt that might remain on the textile to which the yarn is sewn does not cause contamination of that textile since they are made of the same material. As a result, the purity of the textile being disassembled is not impaired, so that the quality of the material is avoided as a result of yarn contamination and the quality thus remains at a maximum.

[0064] According to one embodiment, the thermoplastic polymer melt yarn consists entirely (100%) of polyester. Polyester is used in about half of all textile products. By using thermoplastic polyester filament as a raw material for polymer melt yarn, contamination of parts made of polyester will not occur in about half of the disassembled textile products. As previously stated, it is a very important characteristic for the quality of polyester textiles after disassembly. Additionally, the inventors found the polymer to be very useful as a yarn due to its high tensile strength, average elongation and high flexibility. In addition, polyester can be made into polymer filaments with the desired thermoplastic characteristics, so that the polymer is extremely suitable for use as a melt yarn in the production of textile products that can be disassembled automatically or semi-automatically.

[0065] In another embodiment, the yarn used is 100% PLA, PP or PET(-G).

[0066] In one embodiment, additives or materials to increase thermal conductivity are added to the yarn from the melt. In order to avoid thermal degradation of textile materials during the disassembly phase, the period during which textile products are exposed to heat sources should be minimized. For this reason, it is desirable to increase and accelerate the thermal conductivity of the yarn from the melt without having to change the melting temperature.

[0067] Heat transfer by conduction is described by Fourier's law:

Q = kA dT / d

Q = heat transfer / heat flux (W)

A = cross-sectional area of heat transfer (m<2>)

k = thermal conductivity coefficient (W / (m.K) )

dT = temperature differences per material (K)

d = thickness of the material (in other words, the distance between the cold and hot side) (m)

[0068] Polymers have a low conductivity coefficient of 0.2–0.4 W/(mK). Suitable additives can be used to increase the thermal conductivity of polymers and enable faster and more efficient yarn melting during the disassembly of textile products.

[0069] In one embodiment, one or more additives can be added to the melt yarn to increase thermal conductivity. In one embodiment, said additives are selected from the group of metals, graphite or ceramic materials, as well as any mixtures thereof.

[0070] In one embodiment, the additives are added in a mass percentage that is set between 1% and 80% w/w, preferably between 1 and 70% w/w, preferably between 1% and 20%, more preferably between 5 and 10%. In this way, a yarn with a thermal conductivity of 1–20 W/(m.K) can be obtained.

[0071] Metals have high intrinsic thermal conductivity. Thus, aluminum has a range of 200 W/m.K. Their high densities and high electrical conductivity present opportunities in terms of price fixation, as well as further innovation in terms of applications of portable technology in textiles.

[0072] Metal can be introduced into the quilting yarn in various ways. On the one hand, the metal can be added as a powder during melt spinning, or it can be introduced as a short fiber during the mechanical spinning and twisting process. Finally, it can be added as a coating during sewing in thread finishing processes (after spinning).

[0073] In one embodiment, the melt yarn is coated with an aluminum coating. Techniques for coating yarn with aluminum are known in the art.

[0074] Known techniques include, among others, the "Low Pressure Cold Spray" (LPCS) process, as well as vacuum deposition and printing. Other methodologies are electroless yarn electroplating (a conductive application process for a non-conductive material) or the use of a polymer coating to obtain a more homogeneous coating. Finally, Hye Moon Lee describes a "chemical dissolution process" in which the yarn is pre-treated catalytically to create "spots" on the fiber structure for aluminum atoms to adhere to. The yarn could then be brought to room temperature in a solution of aluminum precursor molecules. As a result, aluminum nuclei may condense at these sites and precipitation may occur. The result of that process is an aluminum film and aggregation on the surface of the yarn and in the fibrous structure. Thanks to this process, the yarn becomes thermally and electrically conductive while maintaining flexibility. In addition, the coating is long-term stable.

[0075] In another or further embodiment, ceramic materials are added to the yarn from the melt. These ceramic materials can be added to the yarn in the form of fillers or powders during the melt spinning process. Examples of useful ceramic materials are oxides such as aluminum oxide or magnesium oxide (Martoxid®), calcium carbonate (Fiberlink®), magnetite (MagniF), aluminosilicate (Silatherm®), boron nitride (Carbotherm®), dry ground mica (Trefil®).

[0076] In another or further embodiment, graphite is added to the yarn from the melt.

[0077] Although not part of the claimed invention, for purposes of illustration, the subject view further carries out a process for producing textile products that can be disassembled automatically or semi-automatically, the polymer melt yarn used is mono- or multifilament. Natural fibers consist of relatively short filaments and should be processed into multifilaments if they are to be used as yarns. Since thermoplastic polymers can in principle be made into infinitely long filaments by extrusion, they provide the advantage that monofilament is already suitable for use as a yarn.

[0078] On the other hand, polymers are also suitable to be processed into melt yarns as multifilaments. In the present invention, the term "multifilament" means that the yarn is made of more than one filament. In a multifilament melt yarn, the filaments will at least partially overlap in the longitudinal direction of the melt yarn. In this way, a stronger melt yarn is obtained, which is not related to the degree of flexibility of the melt yarn. In addition, a stronger melt yarn will also lead to stronger adhesion as a result of sewing or quilting with melt yarn. The number of filaments in multifilament melt yarn depends on the application and the type of textile product that will be produced with it. The physical characteristics (tensile strength and thickness) of the individual polymer filament allow the skilled worker to make an appropriate choice as to the number of filaments to be melt spun.

[0079] The "thickness" of the yarn is described in the present invention by means of mass number and length number. The "mass number" of the yarn corresponds to the mass in grams of 1000 m of yarn, where 1 g / 1000 m is denoted in the technical field as "1 tex". The "length number" of the yarn corresponds to the number of times that a length of 1.6934 m of yarn fits into 1 gram. According to a further development of the subject invention, the thickness of the melt yarn is characterized by a mass number that is set between 0.003 g/m (3 tex) and 1.5 g/m (1500 tex). Preferably, the weight count of the melt yarn is 0.005 g/m (5 tex) to 0.03 g/m (30 tex), 0.03 g/m (30 tex) to 0.3 g/m (300 tex), 0.3 g/m (300 tex) to 0.5 g/m (500 tex), 0.5 g/m (500 tex) to 1 g/m (1000 tex) and/or from 1 g/m (1000 tex) to 1.5 g/m (1500 tex). In a preferred embodiment, the yarn has a mass number set between 250 and 2000 Dtex/3, more preferably between 500 and 1500 Dtex/3.

[0080] The inventors have determined that at those mass numbers yarns from the melt are obtained which are suitable for the production of various textile products with a built-in disassembly function. Thinner melt yarns are therefore particularly, but not exclusively, suitable for delicate sewing such as, for example, when assembling parts consisting of thinner fabrics such as lace or chiffon. Thicker melt yarns are, on the other hand, more suitable for sewing in which heavier parts or parts that are more exposed to wear must be assembled.

[0081] The strength of points that occurs when two parts are sewn together using melt yarn according to the subject invention, which is not part of the invention for which protection is sought, is determined by means of "tensile strength" or both melt yarn and other standard yarns used to obtain stitches. "Tensile strength" is a measure of the maximum tensile force exerted on the yarn ends just before the yarn breaks under the increasing tensile force. According to a further embodiment, the tensile strength of the melt yarn is set between 4 N and 800 N. Preferably, the tensile strength of the melt yarn is 5 N to 50 N, 10 N to 50 N, 4 N to 16 N, 16 N to 160 N, 160 N to 300 N, or 300 N to 800 N. The tensile strength increases as the thickness increases. melt yarn. These tensile strengths guarantee the production of a diverse range of high-quality textile products, where the use of melt yarns provides strong and reliable quilting of parts.

[0082] Yarn "elasticity" describes the maximum increase in length when the maximum pulling force is exerted on the ends of the yarn without breaking the yarn. The elasticity of the melt yarn is important because, on the one hand, one does not want to get a large stitch that cannot be stretched to a lesser degree with the textile parts on which it is present, but, on the other hand, one wants to avoid that the assembled parts can be temporarily stretched as a result of excessive elasticity of the yarn used during sewing. The inventors have determined that when the elasticity of the melt yarn is, according to a further embodiment, less than 25%, for example set between 5% and 30% of the total length of the melt yarn, preferably between 10% and 25%, the melt yarn is obtained with optimal characteristics in terms of sewing flexibility and point integrity.

[0083] According to the invention, a thread spun from a thermoplastic polymer melt is used. A "twisted" yarn is obtained by "twisting" several yarns or filaments, where the yarn consists of one or several filaments and "twisting" refers to the compression together of at least two yarns into a single yarn, in which the characteristics of the resulting composite yarn differ from those of the individual yarns. The resulting melt spun yarn is extremely suitable for the production of textile products that impose high demands on point strength, such as, for example, but not limited to, seat covers and footwear.

[0084] The spinning of one or more melt yarns into one melt yarn is possible in different ways and is generally performed in two stages.

[0085] In the first stage, the yarn is twisted around itself in a mechanical way. In the second stage, the desired number of yarns from the first stage are then taken together and mechanically twisted around each other in the opposite direction compared to the first stage to produce a bundle of the desired thickness. As a result, the filaments in the yarn are tightly twisted into each other and those filaments will be more difficult to break due to friction, and if the filament does break, it will not be able to move due to the twisting. Melt spinning of filaments or yarns therefore substantially increases wear resistance. In addition, a moderately twisted yarn will also become smoother, and as a result, it will glide better when quilting.

[0086] Yarn twisting into the desired melt yarn is possible not only thanks to twisting but, for example, is also possible as a result of yarn entanglement. Of course, other common methods of melt spinning are also possible.

[0087] When spinning is carried out with very many yarns into a single melt yarn, it results in a very strong and/or thick melt yarn that can be used for textile products that require it, such as, for example, but not limited to, parachutes and boat sails.

[0088] The twisting of melt yarn filaments can be fixed, preferably by means of heat treatment, before or after further processing, such as twisting with other filaments or other yarns. Depending on the characteristics of the melt yarn, the temperature of this heat treatment varies between 50° C and 155° C, preferably between 60° C and 100° C. By fixing the twist to the filaments of the melt yarn, it is avoided that the twist is lost during the sewing process due to which knots may appear in the melt yarn during the use of the yarn. This process preferably takes place in an autoclave, under a pressure set between -0.07 and 0.5 MPa.

[0089] According to the invention, a textile product that can be disassembled automatically or semi-automatically will consist of individual pieces, wherein at least some of the individual pieces are attached to each other by means of points, and wherein at least one yarn from a polymer solution is used for the points, wherein the transition of the yarn from the melt from a solid phase to a liquid or semi-liquid phase is at a temperature equal to or higher than the melting temperature of the yarn and wherein the product can be disassembled into individual pieces by means of heating the product or points to a temperature equal to or higher than the melting temperature of the yarn. According to the invention, a yarn whose melting temperature is set between 80° C and 200° C will be used, and whereby the product can be separated into individual pieces by heating the product or points to a temperature equal to or higher than the melting temperature of the yarn. Although not part of the claimed invention, for purposes of illustration, a textile product may be obtained by a process as described above or in which one or more melt yarns are used for the textile product as described above. Those textile yarns can be broken down into high-quality textile parts at the end of their useful or expected life.

[0090] The invention relates to a process for disassembling a textile product as described above or obtained using a melt yarn as described above, where the melt yarn is heated to a temperature equal to or higher than the melting temperature of the melt yarn. When melting yarn, stitching or stitches lose their integrity. Consequently, the stitch will lose its stitching capacity and the product will break up into the different parts that make up the textile product.

[0091] The method for disassembling textile products according to the present invention leads to high-quality recycling products whose mechanical characteristics are not impaired by disintegration and which, in addition, have a high degree of purity thanks to the use of melt yarn. In addition, as previously stated, this leads to a huge financial potential in the recycling of textile products as part of the end-of-life process of those products. The disassembly of textile products and the reuse of high-quality materials leads to enormous financial savings in the processing of textile waste. On the other hand, raw materials for the production of new textile products can be obtained in this way, so that the financial savings continue in the production of new textile products.

[0092] According to the invention, the melt yarn is heated indirectly. For illustrative purposes, direct heating is, for example, possible using a hot air gun or immersing textile products in hot water. According to the invention, indirect heating is, for example, possible by placing the textile product in an oven, or on a holder where warm air passes.

[0093] According to the invention, the disassembly of textile products is performed automatically or semi-automatically. In one embodiment, the textile products are shaken or moved during heating. As a result of the movement, the different parts are automatically separated after melting the yarn from the melt. According to the invention, the disassembly device comprises a heating unit such as a (tubular) oven in which the textile products are preferably moved, for example, by means of a screw conveyor, a drum or a conveyor belt. Optionally, in the disassembly device, it is possible to provide a rotating cylinder for further separation of parts of the textile product. In one embodiment, one or more steam generators may be provided to create a flow of moist air. This can be useful for speeding up the disassembly process. It should be noted that although high atmospheric humidity is desirable in the disassembly device or oven, the textile products should, however, be dry. Wet textile products have a negative effect on the speed of disassembly because wet textiles absorb energy and this latent heat slows down the disassembly process.

[0094] The automation of the process reduces the costs of the disassembly process since here, in contrast to existing recycling procedures, little or no manual work is required. Thanks to the use of a heating unit, a drum and/or a conveyor belt in the disassembly device, textile products for disassembly can be continuously fed into the device. This leads to a continuous or continuous process, which further increases the efficiency of the disassembly process.

[0095] According to a further embodiment, the yarn is removed from the melt after disassembly of the given textile product. Preferably, the yarn is removed from the melt automatically or semi-automatically. This is possible by means of one or more brushes which are present in the disassembly device and along which parts of the textile product can pass. In a further embodiment, washing may be considered. As a result, the contamination of textile materials by melt yarn material will be even less and higher quality textile materials will be retained. In a preferred embodiment, a cooling unit is provided after the heating unit to cool both the products and the removed yarns.

[0096] The device according to the subject view can include a conveyor belt, which is suitable for delivering textile products for disassembly to the heating unit and for shipping the disassembled pieces of those products from the heating unit. According to the invention, the heating unit is provided with heating elements such as infrared radiators etc. to ensure the correct temperature. Furthermore, a drum or screw conveyor can be integrated in the heating unit, for moving textile products through the heating unit (swirling). Additionally, steam generators may be present.

[0097] In the following, the invention will be described by means of non-limiting figures which illustrate the invention and are not intended to be interpreted in a manner that limits the scope of the invention.

EXAMPLES

Example 1

[0098] Table 1 shows the melt yarn according to one embodiment of the present invention and that it can be used for the production of textile products that can be disassembled, such as clothes, but also mattresses, etc. Disassembly takes place by heating the product or points made from the melt yarn to a temperature approximately equal to or higher than the melting temperature of the yarn.

[0099] Other examples or useful yarns are:

Polypropylene yarn with a breaking point of 176° C or higher, a tensile strength of 20 N or 39.5 cN/Tex, 520 Dtex/3. These polyolefin-based yarns can be used for chemical recycling processes and can be used for quilting clothing, accessories and furniture textiles. In addition, this yarn can be made in different Tex (which is higher or lower than the example in question).

[0100] Biological polylactic acid yarn with a breaking temperature of 175° C or higher, tensile strength set between 10 N and 30 N, 500 to 1500 Dtex/3 (depending on requirements). This yarn is biodegradable and made from polyester from biological sources. This yarn, which is available in different dtex, is particularly suitable for quilting clothing, accessories and furniture textiles.

[0101] Bio-polyamide-based yarn with a breaking point of 195° C or higher, a tensile strength of 28 N and 900 Dtex/3. That yarn is a stronger yarn that melts at a higher temperature. As a result, it is particularly suitable for implementation in workwear, in addition to, of course, normal clothing, accessories and furniture textiles. It is available in different dtex.

Example 2

[0102] Disassembly will preferably take place using a device that ensures the correct disassembly temperature. Depending on the type of product to be disassembled, as well as the quantity, a specific device can be chosen.

[0103] Both direct and indirect heating can be applied. Table 2 describes the possible processes that can be applied, depending on the nature of the product and the scale:

Example 3

[0104] Thermally conductive additives or materials can be added to the polymer melt yarn. Examples of such melt yarns are:

Polypropylene homopolymer yarn with 10% calcium carbonate filler. The melting point of the yarn is 176°C, it is available in different dtex.

[0105] Polypropylene homopolymer yarn with 5% micro filler. The melting point of the yarn is 165° C, it is available in different dtex.

DESCRIPTION OF IMAGES

[0106] Fig. 1 shows a schematic illustration of the production of a textile product that can be disassembled automatically or semi-automatically according to the subject representation.

[0107] In this example, a home sewing machine with one needle (1), one upper thread (2) and one lower thread (3) is used. The figure illustrates the formation of a stitch between the first textile material (4) and the second textile material (5) by means of a simple closed stitch (6) in which the upper yarn and the lower yarn cross. A cross-section of the resulting stitch is shown. A closed stitch (6) is formed when the needle (1) with the upper yarn (2) passes through both textile materials (4 and 5) and forms a loop under those materials. Then, the hook (7) turns that loop around the spool (8) on which the lower yarn (3) is wound.

[0108] To obtain the built-in unwinding function, at least one of the upper yarn (2) or the lower yarn (3) should be made of thermoplastic polymer melt yarn. In this figure, the lower yarn (3) is replaced by a melt yarn according to one embodiment of the invention since, in a closed stitch, it is sufficient to replace one of the two yarns used with a melt yarn to obtain a built-in unraveling function according to the method of the invention. The melt yarn from Figure 1 consists of two longitudinally parallel thermoplastic polyester filaments with a melting temperature of 170°C. The filaments are melt spun with a thickness characterized by a mass number of 125 dtex x 2 and a length number Nm of 80/2. The strength of the melt yarn illustrated as bottom yarn (3) in Figure 1 is 11.5 N, and the elongation is between 18 and 21% over the total length of the melt yarn.

[0109] Moreover, this melt yarn is taken here as the bottom yarn (3) and is sewn by a sewing machine for the reverse side of the textile product. Standard yarn was used as upper yarn (2). In the finished textile product, only the upper yarn (2) is visible, and therefore the aesthetic characteristics are not impaired by the use of melt yarn as the lower yarn (3). In this way, the built-in disassembly function is combined with the aesthetic aspects of the standard yarn, without having to make special adjustments for the aesthetic aspects of the textile product or for the production facilities (namely, the sewing machine). In one embodiment, the melt yarn can be used for the top yarn (2) and the bottom yarn (3), wherein the melt yarn is the same yarn or is a melt yarn with different characteristics (eg, in terms of tensile strength, dtex, yarn nature, etc.).

[0110] Figure 2 shows a possible heating unit (8) for use in the described disassembly process, in which the disassembly process is a continuous process for smaller textile products, such as clothing and accessories. In one preferred embodiment, the heating unit (8) will consist of two sections, namely a heating section and a cooling section (not shown in Figure 2). In the heating section of the heating unit (8), the turbulent air flow is obtained by the function (13) of the drum in the device. The textile product is delivered using a conveyor belt (9) that passes through the device. Products are intensively and homogeneously heated using heating elements (10), such as heat resistors, infrared heating, or other indirect heating sources. Forced thermal convection is further increased as a result of moist air flow, ie. hot steam under pressure through the steam generator (11). A collection system (12) for the produced liquid, such as water, can be provided at the bottom of the device. The textile product will pass through a drying oven at a temperature of 60-200° C for a maximum of 5 minutes (preferably less than 3 minutes). The quilting yarn will melt (change its phase) and allow the various components of the product to break down (manually or automatically, for example using a drum device). If the product has filaments made of polymers with a melting temperature in that range, they will also melt and disintegrate.

Claims (5)

Patent claims 1. A method for disassembling a textile product, where the textile products can be disassembled and therefore recycled or reused automatically or semi-automatically, where said textile product is composed of individual pieces, wherein at least some of said individual pieces are attached to each other by stitching, and where said stitching uses spun yarn from a thermoplastic polymer melt, said polymer is a thermoplastic polymer selected from the group of polyolefins, polyesters, polyoxymethylene (POM), polypropylene, polyurethane, polyamide, polylactic acid and their copolymers, said thread from the melt has a melting temperature between 80° C and 200° C, which enables the thread to pass from the melt from a solid phase to a semi-liquid phase at a temperature equal to or higher than the melting temperature of the thread, indicated by the fact that the disassembly of the said textile product is performed by exposing the product to hot air whose temperature is equal to or higher than the melting temperature in a heating unit that is made with heating elements. 2. The method according to patent claim 1, where performing the disassembly of said textile product further comprises exposing the product to steam. 3. The method according to any of the previous patent claims 1 or 2, characterized in that during sewing or quilting, at least one melt thread and at least one standard thread, or at least two different melt threads, are used. 4. The method according to any of the previous patent claims, characterized in that the thread from the melt is made with one or more materials that increase heat conductivity and are selected from the group of metals, ceramic materials and/or graphite. 5. The method according to any of the preceding claims, characterized in that the polymer melt thread has a tensile strength between 4 N and 800 N.